YOU CAN 3D PRINT THIS POCKET ROBOT THAT BLINKS, TALKS AND FOLLOWS YOUR FACE
A palm-sized robot that blinks, breathes and follows your face — community-built since 2021, now with M5Stack hardware support.
by meganetaaana (Shinya Ishikawa)
RoboticsAI
- difficulty
- ●●●○○
- time
- a weekend-plus
- license
- Apache-2.0
- repo
- repo ACTIVE1,628 stars
●●●○○ · a weekend-plus · Apache-2.0 · 1,628 stars · repo ACTIVE
WHAT YOU’LL NEED
- 3D printer + filament — printable parts — files are in the repo
- Electronic parts — full list with part numbers in the repo BOM
- Dev board / microcontroller — runs the project firmware
- Soldering kit + basic tools — one-time buy, serves every future build
Partner
COMPAREE VERDICT
Stack-chan is a genuinely charming desktop robot: it tracks faces with servo-driven eyes, speaks using TTS, and moves with small breathing animations. The hardware is simple — an M5Stack controller, two servos, and a 3D-printed shell — but the character comes from the firmware, which has had years of community polish. The single hardest part is tuning the servos: too tight and the eyes judder, too loose and they drift. The repository contains the firmware and STL files, but practical details like print orientation, infill and servo calibration live in community posts and the Discord. If you have printed articulated models before, this is a weekend project; if you have not, plan for a second weekend debugging servo jitter. The M5Stack Kickstarter campaign turned this into a product, but the open-source version is still the one you can modify — and that is the entire reason to build it.
IN THE REPO
NOT IN THE REPO
- —STL files, firmware and assembly instructions are all in the repository.
- —No PCB — the project uses off-the-shelf M5Stack modules (M5Stack Core2, CoreS3 or ATOMS3).
- —Documentation is in Japanese and English, with community translations.
- —The repository does not specify print settings or filament type — those are community knowledge.
- —Licensed under Apache 2.0: you can build commercially, but attribution is required.
- —M5Stack's Kickstarter version ships as a kit with custom firmware — building your own from the open repo is still free.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Partner · KickstarterHeyGears G1: 10M+ colors and transparent parts in one print, plus UV printing on flat objects. Figures, parts and labels — no painting.
Videos
Stack-chan: the open communication robot for everyone
No official video channel. Community walkthroughs exist on YouTube but are not linked from the repository.
Gallery
Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Read the English README and check the hardware compatibility list (Confirm your M5Stack board is supported before ordering anything.)
- 2.Print the shell and neck joint(STL files are in the repository. Print orientation matters — check community posts if the neck joint does not move smoothly.)
- 3.Flash the firmware and calibrate the servos(Use Arduino IDE or PlatformIO. Servo calibration is the step that takes longest — expect to tweak trim values.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
Partner · KickstarterCORE POWER BANK S: 0.2" thin, 2.8 oz, 5000 mAh with 22.5W fast charging. Semi-solid battery, carbon fiber, IPX7 waterproof.
KNOWN ISSUES
- Buying the wrong M5Stack module. The firmware supports Core2, CoreS3 and ATOMS3 — older M5Stack boards (Basic, Fire) are not in the compatibility list.
- Servo jitter. SG90 servos are cheap but inconsistent — if the eyes judder, try a different brand or add a 100µF capacitor across the power rails.
- Print orientation. The neck joint has to rotate smoothly — if you print it flat, it binds. Community posts suggest printing it upright.
- Assuming the Kickstarter firmware is in the open repo. M5Stack's kit ships with custom features (ChatGPT integration, cloud sync) that are not in the Apache-licensed code.
- No BOM in the repository. The parts list is in the README but does not include suppliers or part numbers — you have to source the servos yourself.
- Japanese-first documentation. The English README is good, but deeper guides and community troubleshooting are often in Japanese first, then translated.
Can I build this without the M5Stack Kickstarter kit?
Yes. The open-source repository contains everything you need. The Kickstarter version has extra cloud features, but the core project — face tracking, TTS, blinking — is all in the Apache-licensed code.
What is the difference between the M5Stack boards?
Core2 and CoreS3 have touchscreens and built-in speakers. ATOMS3 is smaller and cheaper but needs an external speaker. All three work with the firmware.
Do I need to solder anything?
Not if you use the Grove connector on the M5Stack board. If you wire the servos directly, soldering is optional but makes it neater.
How do I stop the servos juddering?
Lower the PWM frequency in the firmware, add a capacitor across the servo power lines, or try a different servo brand. SG90s vary wildly in quality.
Community builds
No community builds yet — be the first, we feature the best ones.
Discussion1
FROM THE COMPAREE TEAM
The firmware has had years of community polish — smooth blinking, breathing animations, face tracking that actually works. If you have built one, what was the single tweak that made the biggest difference?
meganetaaana (Shinya Ishikawa)
Started as a personal project in 2021 to explore servo-driven character animation. The community grew around it, and in January 2026 M5Stack launched it as their first community-created product on Kickstarter.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM23d agoedited
Practical notes from our verification: the repository is active and well-documented in both Japanese and English. The STL files are there, the firmware builds cleanly in PlatformIO, and the M5Stack hardware list is clear. The single biggest missing piece is print settings — infill, orientation, supports — which you have to piece together from community posts. The Kickstarter campaign is real (launched January 2026), but the open-source repo predates it and is still the version you modify. No official YouTube channel; the good walkthroughs are community-made and not linked from the repo.